RUBBER COMPOSITION AND TIRE

The present disclosure aims to provide rubber compositions and tires which provide improved overall performance in terms of wet grip performance and dry grip performance. The present disclosure relates to a rubber composition having a hardness that reversibly changes with water and satisfying the following relationships (1) and (2): Hardness when dry−Hardness when water-wet≥1 (1) wherein each hardness represents the JIS-A hardness at 25° C. of the rubber composition; and tan δ at 70° C. when dry≥0.18 (2) wherein the tan δ at 70° C. represents the loss tangent measured at 70° C., an initial strain of 10%, a dynamic strain of 2%, and a frequency of 10 Hz.